Collaborative Research: Photochemical Silicon Aerosols: Establishing Atmospheric Sources and Significance

这项研究的重点是提高对挥发性甲基硅氧烷(VMS)在大气中的化学和物理转化的了解。挥发性甲基硅氧烷(VMS)是一种高产化学品，用于许多个人护理产品，如除臭剂和乳液。预计这项研究的结果将有助于更好地评估VMS的去向和运输问题，这对于了解VMS的使用增加对环境和健康造成的后果至关重要。该项目的目标是评估实验室和环境大气气溶胶中氧化的VMS的化学形态和丰度。这项研究有望证实环境中有机硅化合物形成的颗粒的存在，建立城市和远程氧化条件下近环境条件下的气溶胶产量，确定这类二次有机气溶胶的最佳气溶胶示踪化合物，并将这一努力的结果整合到一个最先进的光化学网格模型中，该模型将能够在从城市机场到大陆的范围内预测VMS在氧化过程中的命运。这项研究包括爱荷华大学使用氧化流动反应器(OFR)的实验室研究和科罗拉多大学环境实验室的实验，以探索VMS的氧化化学。在纽约市大都会地区为期四周的夏季部署期间，将对VMS及其气体和冷凝相氧化产品进行室外环境采样。从这项研究中获得的科学见解将被纳入社区多尺度空气质量(CMAQ)建模系统，该系统将导致更好地预测个人护理产品中的气溶胶形成。该项目由NSF大气化学计划和既定的激励竞争研究计划(EPSCoR)联合资助。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This research is focused on improving the understanding of the chemical and physical transformations of volatile methyl siloxanes (VMS) in the atmosphere. Volatile methyl siloxanes (VMS) are high production chemicals used in many personal care products such as deodorants and lotions. The results of this research are expected to lead to a better assessment of the fate and transport issues important for understanding the environmental and health consequences of the increasing use of VMS.The objective of this project is to assess the chemical speciation and abundance of oxidized VMS in the laboratory and in ambient atmospheric aerosols. This research is expected to confirm the presence of particles formed from ambient organosilicon compounds, establish aerosol yields at near-ambient conditions under urban and remote oxidation conditions, determine the best aerosol tracer compounds for this class of secondary organic aerosols, and integrate the results of this effort into a state-of-science photochemical grid model that will enable the prediction of the fate of VMS upon oxidation at scales ranging from urban airshed to continental.This research includes laboratory studies at the University of Iowa using an oxidative flow reactor (OFR) and experiments in the University of Colorado environmental chambers to probe the oxidation chemistry of VMS. Outdoor ambient sampling for VMS and its gas- and condensed-phase oxidation products will be conducted during a four-week summertime deployment in the New York City metropolitan area. The scientific insights gained from this research will be incorporated into the Community Multiscale Air Quality (CMAQ) modeling system that will lead to better predictions of aerosol formation from personal care products.This project is jointly funded by the NSF Atmospheric Chemistry Program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.